It is known in the art to employ supported alkali metal catalysts for such conversions as propylene dimerization. In addition, the use of alkali metal carbonates as catalyst supports is known in the art. However, such catalysts as alkali metals supported on alkali metal carbonate supports do not always give high yields of the desired products, either due to low feed conversion, low product selectivity or both. In addition, the use of alkali metal carbonates alone as catalyst supports has been disadvantageous, especially in fixed bed operations for the reason that the supports do not have sufficient strength. Alternatively, prior art olefin dimerization catalyst systems have been limited to use in batch-type reaction due to the catalyst solubility or the fragile nature of prior art particulate catalysts.